From c96a48385d53089ee9977dd0bce82a9493984484 Mon Sep 17 00:00:00 2001 From: Cong Wang Date: Thu, 26 Oct 2017 18:24:29 -0700 Subject: [PATCH] net_sched: use tcf_queue_work() in basic filter Defer the tcf_exts_destroy() in RCU callback to tc filter workqueue and get RTNL lock. Reported-by: Chris Mi Cc: Daniel Borkmann Cc: Jiri Pirko Cc: John Fastabend Cc: Jamal Hadi Salim Cc: "Paul E. McKenney" Signed-off-by: Cong Wang Signed-off-by: David S. Miller --- net/sched/cls_basic.c | 20 +++++++++++++++++--- 1 file changed, 17 insertions(+), 3 deletions(-) diff --git a/net/sched/cls_basic.c b/net/sched/cls_basic.c index d89ebafd2239..f177649a2419 100644 --- a/net/sched/cls_basic.c +++ b/net/sched/cls_basic.c @@ -34,7 +34,10 @@ struct basic_filter { struct tcf_result res; struct tcf_proto *tp; struct list_head link; - struct rcu_head rcu; + union { + struct work_struct work; + struct rcu_head rcu; + }; }; static int basic_classify(struct sk_buff *skb, const struct tcf_proto *tp, @@ -82,15 +85,26 @@ static int basic_init(struct tcf_proto *tp) return 0; } -static void basic_delete_filter(struct rcu_head *head) +static void basic_delete_filter_work(struct work_struct *work) { - struct basic_filter *f = container_of(head, struct basic_filter, rcu); + struct basic_filter *f = container_of(work, struct basic_filter, work); + rtnl_lock(); tcf_exts_destroy(&f->exts); tcf_em_tree_destroy(&f->ematches); + rtnl_unlock(); + kfree(f); } +static void basic_delete_filter(struct rcu_head *head) +{ + struct basic_filter *f = container_of(head, struct basic_filter, rcu); + + INIT_WORK(&f->work, basic_delete_filter_work); + tcf_queue_work(&f->work); +} + static void basic_destroy(struct tcf_proto *tp) { struct basic_head *head = rtnl_dereference(tp->root); -- 2.34.1